The sensory organs and the nervous system in tapeworms are poorly developed

The sensory organs and the nervous system in tapeworms are poorly developed, and the digestive organs are absent. What do these signs indicate?

This indicates a parasitic lifestyle in the intestines that tapeworms lead. They do not need a developed nervous system and sensory organs, because they do not need to monitor the external environment and respond to changes in it. Their external environment is constant. The absence of digestive organs indicates that they use other people’s digestive organs and receive nutrients in a ready-to-digest form.